The rates on The Hours do not change for festive dates. No seasonal surcharges, ever. What changes is the minimum: New Year's Eve is held for one guest only, at Night Into Morning or longer, and Christmas and Valentine's begin at six hours, because no evening worth the date leaves after three. The notice changes too: these dates are typically spoken for weeks in advance, so the early note wins the evening.
A festive date pairs naturally with the longer invitations: six hours carries a dinner past midnight, Night Into Morning lets the new year begin properly, and a suite saves anyone a cold ride home.
One thing never appears on the bill: the shape itself. Every experience on this site is included in the hours. The only additions are real ones, agreed in advance: date expenses such as dinner and travel, a suite when I arrange one, or specific items an evening asks me to buy.